A polymeric micelle or nanosphere composed of a hydrophilic/hydrophobic type block polymer wherein a hydrophilic polymer like polyethylene oxide is combined with a hydrophobic polymer at the molecular level is now attracting attention as a carrier for drug delivery or the like. Said polymeric micelle and nanosphere have been prepared from a hydrophilic/hydrophobic type block polymer wherein a hydrophilic polymer is combined with a hydrophobic polymer at the molecular level.
In conventional processes to produce a hydrophilic/hydrophobic type block polymer, however, there is a limitation on the species of terminal functional groups to be introduced, and there have only been proposed block polymers whose functional groups are restricted to methoxy or hydroxyl group. If optional functional groups were successfully introduced onto the micelle surface at an optional proportion, it would become possible to provide a functional polymeric micelle which could be useful for drug delivery to certain organs.
Thus, the object of this invention is to provide a block polymer, which has functional groups on both ends of its main chain, as a polyfunctional polymer which is capable of forming a polymeric micelle.